Partnership exceeds pollution reduction targets for phosphorus, sediment, but falls short for nitrogen

by Joan Smedinghoff

July 30, 2018

The Environmental Protection Agency (EPA) recently released the results of its check-in on the progress the six watershed states, the District of Columbia and federal agencies have made toward meeting the goals of the Chesapeake Bay Total Maximum Daily Load (Bay TMDL), or pollution diet. According to data submitted by Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia, as well as the District of Columbia, the Chesapeake Bay Program (CBP) partnership exceeded its halfway goal for reducing phosphorus and sediment as measured under the current suite of modeling tools, but it fell short for nitrogen.

Under the Bay TMDL, the six watershed states and the District of Columbia have agreed to develop short-term goals, called two-year milestones, to check in on progress being made to reduce pollution. The midpoint assessment looks at the states’ and D.C.’s final 2016-2017 milestones and 2017 progress data (computer simulations based on reported pollution reducing practices) to determine if practices are in place to achieve 60 percent of the necessary pollution reductions. This is the midpoint to 2025, the year by which the six states and the District of Columbia need to have 100 percent of pollution reducing practices in place.

Excess nitrogen, phosphorus and sediment are among the leading causes of the Bay’s poor health. Nitrogen and phosphorus can fuel the growth of algae blooms that lead to low-oxygen “dead zones” in deep waters. Sediment can suffocate shellfish and block sunlight from reaching underwater grasses, which are important habitat for blue crabs. Pollution-reducing practices in backyards, in cities and on farms can lower the flow of nitrogen, phosphorus and sediment into waterways.

Milestones evaluation

The EPA has conducted evaluations of the six watershed states’ and District of Columbia’s two-year milestones as well as assessments of the state-wide wastewater, agricultural, stormwater and trading/offset programs. Based on these evaluations, EPA has highlighted achievements and shortfalls using a ranking system to determine the level of EPA’s program oversight for these sectors in each of the six states and D.C.

2017 progress data

The CBP announced in July 2018 that while computer simulations showed a drop in the amount of nitrogen entering the nation’s largest estuary, the partnership fell short of its pollution reducing target for nitrogen by 15 million pounds. According to the partnership’s Watershed Model, pollution controls put in place between 2009 and 2017 in Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia and the District of Columbia have lowered nitrogen, phosphorus and sediment loads by 11 percent, 21 percent and 10 percent, respectively.

Practices are currently in place to achieve 40 percent of the nitrogen reductions, 87 percent of the phosphorus reductions and 67 percent of the sediment reductions necessary to attain applicable water quality standards as compared to 2009, the year before the Bay TMDL was established.

The final phase of the pollution diet

The six watershed states and the District of Columbia are moving into the third phase of the Bay TMDL, using the information from the midpoint assessment to write their watershed implementation plans (WIPs). WIPs are detailed plans, developed by the states and D.C. in conjunction with local and federal partners, with specific timelines for implementing and achieving pollutant load reductions, and will carry them through 2025 to meet their water quality goals.

The EPA will continue to measure progress through two-year milestones. Should the states or D.C. need to modify their commitments between when they finalize their WIPs and 2025, they can do so through their two-year milestones.

Learn more about the midpoint assessment and 2017-2017 milestone evaluations.